discover.c

/*
 *
 *  GattLib - GATT Library
 *
 *  Copyright (C) 2016-2024  Olivier Martin <olivier@labapart.org>
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include <ctype.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>

#ifdef GATTLIB_LOG_BACKEND_SYSLOG
#include <syslog.h>
#endif

#include "gattlib.h"

#define BLE_SCAN_TIMEOUT   10

static const char* adapter_name = NULL;

// Declaration of thread condition variable
static pthread_cond_t m_connection_terminated = PTHREAD_COND_INITIALIZER;

// declaring mutex
static pthread_mutex_t m_connection_terminated_lock = PTHREAD_MUTEX_INITIALIZER;

static void on_device_connect(gattlib_adapter_t* adapter, const char *dst, gattlib_connection_t* connection, int error, void* user_data) {
	gattlib_primary_service_t* services;
	gattlib_characteristic_t* characteristics;
	int services_count, characteristics_count;
	char uuid_str[MAX_LEN_UUID_STR + 1];
	int ret, i;

	GATTLIB_LOG(GATTLIB_INFO, "Connected to bluetooth device '%s'", dst);

	ret = gattlib_discover_primary(connection, &services, &services_count);
	if (ret != GATTLIB_SUCCESS) {
		GATTLIB_LOG(GATTLIB_ERROR, "Fail to discover primary services.");
		goto EXIT;
	}

	for (i = 0; i < services_count; i++) {
		gattlib_uuid_to_string(&services[i].uuid, uuid_str, sizeof(uuid_str));

		GATTLIB_LOG(GATTLIB_INFO, "service[%d] start_handle:%02x end_handle:%02x uuid:%s", i,
				services[i].attr_handle_start, services[i].attr_handle_end,
				uuid_str);
	}
	free(services);

	ret = gattlib_discover_char(connection, &characteristics, &characteristics_count);
	if (ret != GATTLIB_SUCCESS) {
		GATTLIB_LOG(GATTLIB_ERROR, "Fail to discover characteristics.");
		goto EXIT;
	}
	for (i = 0; i < characteristics_count; i++) {
		gattlib_uuid_to_string(&characteristics[i].uuid, uuid_str, sizeof(uuid_str));

		GATTLIB_LOG(GATTLIB_INFO, "characteristic[%d] properties:%02x value_handle:%04x uuid:%s", i,
				characteristics[i].properties, characteristics[i].value_handle,
				uuid_str);
	}
	free(characteristics);

EXIT:
	gattlib_disconnect(connection, false /* wait_disconnection */);

	pthread_mutex_lock(&m_connection_terminated_lock);
	pthread_cond_signal(&m_connection_terminated);
	pthread_mutex_unlock(&m_connection_terminated_lock);
}

static int stricmp(char const *a, char const *b) {
    for (;; a++, b++) {
        int d = tolower((unsigned char)*a) - tolower((unsigned char)*b);
        if (d != 0 || !*a)
            return d;
    }
}

static void ble_discovered_device(gattlib_adapter_t* adapter, const char* addr, const char* name, void *user_data) {
	const char* reference_mac_address = user_data;
	int ret;

	if (stricmp(addr, reference_mac_address) != 0) {
		return;
	}

	GATTLIB_LOG(GATTLIB_INFO, "Found bluetooth device '%s'", reference_mac_address);

	ret = gattlib_connect(adapter, addr, GATTLIB_CONNECTION_OPTIONS_NONE, on_device_connect, NULL);
	if (ret != GATTLIB_SUCCESS) {
		GATTLIB_LOG(GATTLIB_ERROR, "Failed to connect to the bluetooth device '%s'", addr);
	}
}

static void* ble_task(void* arg) {
	char* addr = arg;
	gattlib_adapter_t* adapter;
	int ret;

	ret = gattlib_adapter_open(adapter_name, &adapter);
	if (ret) {
		GATTLIB_LOG(GATTLIB_ERROR, "Failed to open adapter.");
		return NULL;
	}

	ret = gattlib_adapter_scan_enable(adapter, ble_discovered_device, BLE_SCAN_TIMEOUT, addr);
	if (ret) {
		GATTLIB_LOG(GATTLIB_ERROR, "Failed to scan.");
		return NULL;
	}

	// Wait for the device to be connected
	pthread_mutex_lock(&m_connection_terminated_lock);
	pthread_cond_wait(&m_connection_terminated, &m_connection_terminated_lock);
	pthread_mutex_unlock(&m_connection_terminated_lock);

	return NULL;
}

int main(int argc, char *argv[])
{
	char* device_address;
	int ret;

#ifdef GATTLIB_LOG_BACKEND_SYSLOG
	openlog("gattlib_discover", LOG_CONS | LOG_NDELAY | LOG_PERROR, LOG_USER);
	setlogmask(LOG_UPTO(LOG_INFO));
#endif

	if (argc != 2) {
		printf("%s <device_address>\n", argv[0]);
		return 1;
	}

	device_address = argv[1];

	ret = gattlib_mainloop(ble_task, device_address);
	if (ret != GATTLIB_SUCCESS) {
		GATTLIB_LOG(GATTLIB_ERROR, "Failed to create gattlib mainloop");
	}

	return 0;
}